Channel Protocol command in EtherChannel? is that new?

[JoshGarmonCiscoCCNA]

hello

i've never seen the "channel protocol lacp/pagp" command before in all the study material i've seen

i've seen and configured EtherChannels myself without it

interface range ____

channel-group _ mode ___

what's going on with this? 

[paul driver · Accepted solution]

Hello

Channel protocol  -lacp/pagp

I think there isnt any need for this command in aggregation ports. as the channel protocol is negotiated with the active/passive or desirable/auto  int the channel-group x mode command.

If you set the same protocol on the physical interfaces>

int /x/
channel-protocol pagp
channel-group x mode desirable/auto

or
int /x/
channel-protocol lacp
channel-group x mode active/passive

then its allowed, however is you set the reverse it wont be.

int /x/
channel-protocol pagp
channel-group x mode active/passive


My view , I think this can be applied to single interfaces facing some server but its not applicable in present ehterchanneling

res
Paul

[JoshGarmonCiscoCCNA]

in CCNA material, i've never seen it

it was actually a CCNP guide where i saw it

seems like it doesn't do anything

[kam aujla]

The channel-Protocol command in not necessary, the ether channel will form just fine without it. The reason for the channel-protocol command was that people found the various terms such as Active/Passive/Desirable/Auto/On etc confusing, which follow when you type channel-group X mode ? Therefore some bright guy came up with the channel-protocol command, so that when this command is on an interface, the channel-group X mode will only accept commands which go with the protocol you define. Eg. if you selected channel-protocol to be LACP, it will only accept the active/passive argument with the channel-group command, nothing else. So you can't accidentally specify the protocol to be lacp and then turn round any try to use the mode desirable with the channel-group command.

See below from cisco switch: see it rejected the desirable argument/because the protocol is lacp

ALS2(config)#int fast 0/20
ALS2(config-if)#switchport mode access
ALS2(config-if)#channel-protocol lacp
ALS2(config-if)#channel-group 20 mode desirable
Command rejected (Channel protocol mismatch for interface Fa0/20 in group 20): the interface can not be added to the channel group

[bsapida]

Thanks for Clarifying, Kam! I have same question on my staud and your answer is perfect (i did tried it and you are correct on this one).. channel-protocol is not required on this configuration as long as active/passive or desirable/auto are correctly configure